Siege of Viana

The Siege of Viana was a military conflict fought between the Kingdom of Navarre and the Earl of Lerin's forces loyal to Ferdinand II of Aragon. The Navarrese were led by guest general Cesare Borgia from the Papal States, and although they won the battle, Borgia was killed.

Background
In, a treaty between the Navarrese rulers and the Castilians Ferdinand promised to stop warring on Navarre or Béarn, and in exchange Louis II de Beaumont was to hand over some strategic fortresses in exchange for new lands in Granada. However, when the promise was reneged, in an attempt to restore royal authority and patrimony, the king met with the resistance of the defiant count Louis of Beaumont, whose estates where subsequently confiscated.

John III of Navarre gave command of an army of 10,000 troops to the guest general and his brother-in-law Cesare Borgia, who had been exiled from the Papal States. Borgia besieged the castle of Viana, which was a stronghold of Beaumont and the Lerin forces. Cesare excitedly hoped that he could pacify the castle and regain the support of the French and march back into Rome.

Siege
The Castel Viana was a large fortified palace in Viana held by Louis de Beaumont and besieged by Cesare Borgia's army of some 10,000 men. The castle was an extremely strong natural fortification and essentially impenetrable at the time. As a result, Cesare besieged the castle to weaken the forces inside, counting on a desperate surprise attack.

Cesare's forces rushed into the city and boarded onto the walls, and victory was certain for them. However, it was not enjoyed by Cesare. Assassin Ezio Auditore da Firenze, who had followed him from Italy, threw him over the castle walls and killed him. Despite the death of Cesare Borgia, the Navarrese won a clear victory.